Looks interesting, though I think it needs one function to become truly useful for scripted geometry.
A function/command that rotates the selected cube, AGAINST the selected face; or, selects the specified face on the current cube selection.
-OR-
A function/command that allows the user to edit any corner/face of the selected cube, regardless of the face selected.

At the moment, the major limiting factor is that you have to have the proper face selected manually to edit the face/corner of a cube.
(i.e. My Cube-Art script could be modified to manipulate cubes, but it would be limited to manipulating only the selected face/corners of each cube. With the exception of flipping/mirroring the cube, it couldn't change the other faces.)

some things that maybe be helpful (aka a wish list):
Pasting
multi copy (allows for more than one copy buffers (like a clipboard))
paste void (paste items in the copy buffer on the map only in squares that are void(have no cubes in them)in selected area)
paste over (paste items in the copy buffer on the map only in squares that are not void)
paste tex (paste only the texture of the items in the copy buffer, no geom changes to selected area)
mod ctr pt (allows you to change which corner the modification point is on, (the orange box))
ent paste (allows you to paste an ent on the selected side of another ent (when that ent is selected) instead of replacing it)

textures
swap tex (allows you to select an area and do a texture swap (only in selected area)) (useful when creating a red and blue base :)
tex modify (allows you to in game play with a texture (scale size color etc) and then either save as copy (creates a new texture in the texture slot) or saves over the current one)
cfg write (allows you to select particular textures from the main texture pool (possibly reads the whole map and sees what textures are used) and writes a cfg for you (only with those texture that are chosen (aka does a texturerest and defines every texture)))

light
light group(allows you to set groups of lights to be chain together (modifying one will modify them all)- (will not be able to be a mvar because it will mess the headerfile up but it could be in the config))
ami light (allow for amibient lights (lights that dont cast shadows) (i no this with cause map reading problems, but u could save maps as *.ogs, and then export for cube to *.ogz, cuz lightmaps are saved to the map so missing lights does not matter ;)
color (allows you to see the color of a light ent in the entmod menu (in the upper corner), so that you can better determined the color (the changing of the wiresphere is noble but many times inaccurate or out of date, plus it some times hard to see))

misc
presets (creates a menu pop up that shows (like the model menu) saved copy buffers (ie a sphere, a column, etc - basic shapes (these could be saved somewere in the sauer direct as *.pst or w.e.), allow them to be saved under a tab called user (so you dont have to run to another map and copy it, or create it your self))
model view (allows a full rendered (using render to texture) and rotatable model when in the model menu (so u can see the model you are selecting))
muli select(allows muli select for ents (kinda already done, but make it easier to select them (ie hold shift+click)) also allow moving of these selected ents)

this is all i could think of at this point ;p

chasester

Ps i love the mod btw ;)

UPDATE: 'heightmap 2' for In-script heightmapping
Demo video included

an idea i had while reading about this: use this to create 'modules' like castles pieces, trees, bridges, etc.. to be able to piece together a city. idk just some random idea i had.

Working on fixing bugs for now.
Yes, fixed /entset_pos, works again, and some other stuff
And you can force editing by enabling /forceoctaedit or(and) /forceentedit even when you're not in edit mode. Useful when you want to use editing script.

http://www.youtube.com/watch?v=4-EM1fUXIao